In reference to The topical use of insulin accelerates the healing of traumatic tympanic membrane perforations

We would like to address the article titled “The Topical Use of Insulin Accelerates the Healing of Traumatic Tympanic Membrane Perforations,” by Araujo et al. Their work is very interesting and provided a new treatment method for traumatic tympanic membrane perforations (TMP). This study showed that topical application of insulin can shorten the closure time and increase the thickness of the eardrum. However, it did not improve the closure rate compared to that of the control group. We considered whether moist/wet eardrum environments resulting from certain solutions can aid eardrum healing. Yamazaki et al. found that topical application of ofloxacin otic drops significantly shortened the closure time. Similarly, in a recent clinical study we demonstrated that topical application of ofloxacin otic drops significantly shortened the closure time and improved the closure rate of large traumatic TMPs. In addition, we did not observe an increase in the infection rate of the middle ear. This study did not show that ofloxacin can accelerate the healing of the eardrum. We speculate that eardrum healing was similar between topical application of insulin and topical application of ofloxacin otic drops. They both provide a moist/wet eardrum environment, which subsequently facilitates TMP healing. In skin wound studies, it was suggested that moist/ wet wounds facilitate the proliferation and migration of epithelial cells and fibroblasts as well as enhance revascularization. Collectively, these factors lead to eardrum healing. Thus, we believe that using a saline group as a control would have been more convincing than the random control group chosen. We suggest that this be changed in future studies.